Espresso machine



FIG. 1 is a top, front, and left side perspective view of an espresso machine showing my new design;

FIG. 2 is a right side elevational view thereof on a reduced scale; and

FIG. 3 is a rear elevational view thereof on a reduced scale; and

FIG. 4 is a bottom plan view thereof. 

The ornamental design for an espresso machine, as shown and described. 